Computational fluid dynamics (CFD) analysis of a solar air heater has been carried out using artificial roughness in the form of thin circular wire in V-shaped, V-shaped with gap, Multi v-shaped ribs and Multi v-shaped ribs with gap geometries . The effect of these geometries on heat transfer and friction factor was investigated, Comparison of CFD data with Dittuse-Boelter empirical correlation and Blasius equation for smooth duct has been done. Renormalization k-epsilon model (turbulence model) is used to predict heat transfer and friction factor in the duct as results based on this model have been found in good agreement with that of experimental.